Signal controlling mechanism and system



7 Sheets-Sheet l INVENTOR5 ATTORNEi Jan. 10, 1-939. H l. TURNER ET AL SIGNAL CONTROLLING MECHANISM AND SYSTEM Filed July 20, 1934 FIG-1 Jan. 10, 1939. H. l. TURNER ET AL SIGNAL CONTROLLING MECHANISM AND SYSTEM Filed July 20, 1934 7 Sheets-Sheet 2 HflRK/SO/V TURNER BY ERNEST Rf FAEfSERG INVENTORS as 5 o e m H ATTORNEY Jan. 10, 1939. H. l. TURNER ET AL SIGNAL CONTROLLING MECHANI SM AND SYSTEM Filed July 20, .l934 7 Sheets-Sheet 5 Q0 flmufiomkzou J50 51.5 0...

INVENTORS HARRISON TURNER I gum/var IF. FR8R6 ATi'ORNEY Jam 10, 1939. H. l. TURNER ET AL 2,143,658

SIGNAL CONTROLLING MECHANISM AND SYSTEM Filed July 20, 1934 7 SheetsShee t 4 NORMAL CYCLE ARTERIAL HK-BHWAT \x I\\\\\\\\\\\\\\\\\\\\ RE N AMBER CLEAR IIIHIIIHIIJIIHIH \RCD r mam TURN ARROW INTERSECTING HlGHWAY 6 i L\\\\\ AGREEN o l -AMbER "\.E AR 1 F aao "sToP ARTERIAL I'HGHWAY REEN go AM BER CLEAR ED "5T0?" \RKSHT TURN ARROW E$TRIAN PEP\0D \NTERsEcTmG H\GHWAY cam-2w go" -AME E.R CLEAR o RED Sr P INVESTORS Fla-B HARP/SON TURNER v w [RA/557' A? FFEEEEE/FG Jan. 10, 1939. H TURNER ET AL 2,143,668

SIGNAL CONTROLLING MECHANISM AND SYSTEM Filed July 20, 1934 7 Sheets-Sheet PEDESTRIAN PEFUOD ARTEmAL MOVEMENT m me:

RED s'goP AMBER CLEAR mam '60" }ONE. CTCLE E] M [:1 [3 El 2% LI Li Li [J 1 C'TCLE WITHOUT MINOR HIGHWAY Penny ARTER! L HIGHW Y GREEN (so Q AMBER cLEAg 44,2. n RED 6T0? 456 460 PRINCIPAL l-HGHWAY n 0 4-58 REEN 3G0" MEaER C\.E.AR RED "OTOP" Ml OR HIGHWA 456 u 45 RED sToP 451 CYCLE WITH MINOR meu PERm FIG?" 40 \flL IG REEN ao AMBER "CLEAR am STOP" PRlNC\PAL HUSHWAY GREEN "so AMBER CLEARI INVENTORS RED STOP H/W/F/SO/V TURNER mf'RNfST R FREEBERG GREEN-.60

AMBER cLEARi RED 4 ATTORNEY M\NO H\GH A Jan. 10, 1939. H. TURNER ET AL 2,143,663

SI-GNAL CONTROLLING MECHANISM AND SYSTEM Filed July 20, 1934 7 Sheets-Sheet 6 Y HRTERIGL movamm'r mazvic mqn GREEN Gd INVENTOR?) ATTORNEY.

Jan. '10, 1939. H. TURNER ET AL 2,143,663

SIGNAL CONTROLLING MECHANISM AND SYSTEM Filed July 20, 1934 '7 Sheets-Sheet '7 EP 314- f 320 6| ill-265] H.LTU R N ER' ERFRE EB ERG "*{VENTORS WBY' Fl 6 '3 ATTORNEY Patented Jan. 10, 1939 UNITED STATES PATENT OFICE SIGNAL CONTROLLING SYSTEM MECHANISM AND Application July 20, 1934, Serial No. 736,266

16 Claims.

This invention relates to signal controlling mechanism and system, and more particularly to systems and equipment for controlling signals employed for governing highway traffic.

Such signaling systems are sometimes considered as falling into one or the other of two general classes, mechanism and systems falling within one of which classes will be hereinafter designated as being of the pretimed" or timed cycle type and that within the other of which will be hereinafter referred to as the trafiic responsive or trafiic actuated type; theword traffic thus employed being intended to allude both to vehicular and to pedestrian traflic.

It is an important object of this invention to provide a signal controlling system andmechanism therefor, whichis susceptible of adjustment and adaptation, readily accomplished by users of ordinary intelligence and without special facilities, for the purpose of meeting the greatest practicable proportion of the diverse circumstances and conditions presented in efforts to promote safe and expeditious movements of highway traflic.

It is another important object to provide highway traffic signal controlling mechanism which is suited for certain combinations of pretimed cycle operation with traffic responsive service.

It is a further important object to-provide simple and readily applied means whereby highway traiiic signal controllers of certain existing well-known and widely used types may be readily and inexpensively adapted for tramc responsive service.

It is a further object to provide a signal controlling system involving the use of one or more push buttons or other circuit controllers whereby normal pretiming of a sequence of light or other signal aspects for governing movement of vehicles may be changed to a sequence including an added so-called pedestrian period during which both vehicle and pedestrian movements will be suitably governed and guided.

A further object is to provide means for efs fecting signal display during a so-called pedestrian period such as to effect clearance of the intersection and/or needed portions of highways to permit simultaneous pedestrian movements in and through several or all possible channels.

Another object is to provide means whereby least disturbance will result in the movement of traffic in a channel deemed to have superior importance (as, for example, that of an arterial highway), resultant from interruption of the normal course of a predetermined cycle of changes of signal aspects, such as may be caused by the actuation of traific responsive contacts, by inclusion of any special period (such as a pedestrian period) only at a predetermined stage of such normal cycle.

A further important object is to provide means whereby differing pretimed cycles of signal aspects may be selectively rendered effective, through actuation of traffic responsive contacts or otherwise, and whereby differences between such differing cycles may reside in the number and/or the character and/or the duration of any or all of the component signal aspects.

It is a still further object to provide means whereby the display of any signaling aspect occurring because of actuation of traiiic responsive contacts will be preceded by a warning signal for traffic in the channel or lane for which a permisslve or go signal immediately preceded.

Still other objects are to provide so-called memory of actuation of traflic responsive contacts; delay of such memory feature whereby actuation of trafiic responsive contacts later than apredetermined stage of a given cycle will not cause alteration of the characteristics of the cycle then in progress but will suitably alter the next succeeding cycle, and whereby during the course of a cycle the characteristics of which have been or are to be modified resultant from such contact actuation, further contact actuation occurring before a predetermined stage of such cycle will not affect the characteristics of the next succeeding cycle; to provide for maintenance of substantially synchronous relationship between one and another of a plurality of traific signal controllers having the foregoing characteristics, or between such controllers and a master or a central office controller; to provide a type of traffic signal controller which will cause display of a signal for directing certain trafiic (as, for

example, a right turn arrow) at all times except during some abnormal period (as, for example, a pedestrian period)*; to provide means whereby the overall length of the operating cycle of trafiic controllers embodying any or all of the foregoing characteristics may be increased or decreased from a master point or central office, or, whereby, in lieu of such increase or decrease, the normal signaling cycles may be correspondingly suspended, and be replaced by desired intermittent or flashing signals; to render trafiic responsive contacts ineffective for altering cycle characteristics during conditioning for such intermittent or flashing signals; to provide traiiic signal controlling mechanism whereby any or all of the foregoing revisions of operating characteristics may be accomplished without utilization of change gears or other means of such character as to present opportunities for inadvertent disarrangement of intended cycle characteristics incidental to substitution of cycles of one characteristic for those of another.

A further important object of this invention is to provide improved timer and circuit controlling mechanism which, for the accomplishment of all, any one or of any group of the foregoing objects, shall be of greater effectiveness, more reliable, composed of a smaller number of parts severally characterized by strength, durability and facility of assemblage, as well as amenable to a low cost of manufacture.

Other and more specific objects and advantages will appear in the hereinafter following description of an illustrative embodiment of this invention, or will be apparent to those skilled in this art.

For the purpose of enabling this invention to be more readily understood, an embodiment.

thereof is shown in the annexed drawings and hereinafter described, however, such embodiment, though practical, is by no means the only one which the invention may assume, wherefore the invention is not confined to any strict conformity with the more or less diagrammatic representations of the drawings but may be changedand modified in various particulars so long as such changes and modifications make no material departures from the invention, as more particularly set forth in the annexed claims. 1

In the accompanying drawings, like parts are designated by the same reference characters throughout the several views in which Figure 1 is a front elevation of a traffic signal controller embodying this invention;

Fig. 2 is a somewhat diagrammatic isometric view of the signal mechanism shown in the righthand portion of Fig. 1;

Fig. 3 is a schematic representation of circuit connections suitable for association with the traffic signal controller of Fig. 1, together with signal lamps, trafiic responsive contacts and a master controller arranged in cooperative relationship therewith;

Fig. 4 is a schematic representation of a simple manner of associating the timer mechanism of Fig. 1 with a pair of signal lamps;

Fig. 5 is an enlarged view of one of the cam assemblies of Fig. 2, with certain parts broken away;

Fig. 6 is a perspective view of one of the spacer rings of Fig. 5;

Fig. '7 is a chart representative of the compo nent periods which comprise a cycle of the operation of the system arranged in accordance with Figs. 1, 2 and 3, without .a pedestrian period;

Fig. 8 is a chart representative of a similar cycle including a pedestrian period;

Fig. 9 is a chart representative of the traffic movements permitted through the association of a group of trafiic signal controllers with a master controller, in accordance with Fig. 3;

Fig. 10 shows another type of street intersection for control of traffic to which systems in accordance with Figs. 1, 2 and 3 may be readily adapted;

Fig. 11 is a chart showing the relative characteristics of component periods of a system similar to that of Figs. 1, 2 and 3, but arranged for use at an intersection such as indicated in Fig.

10, substituting a go period for a minor intersecting highway for the right turnsignals and the pedestrian period of said prior figures;

Fig. 12 is a chart, similar to Fig. 9, representative of the trafiic movements permitted through the association of a group of t'raffic signal controllers with a master controller in accordance mech'anism CD, the signal circuit controlling mechanism SC responsive thereto, the pedestrian memory relay P and the flashing service control timer mechanism CD. -The timer mechanism CD includes means for establishing the relative durations of the respective periods or components of a cycle of the operation of the controller, together with facilities for manually altering the relative durations thereof; which facilities include the dial I and the arms I49, I5I, I52 and I53 associated therewith.

As shown in Fig. 3, the pins I5I', I52 and I53 are secured to the free ends of the arms I5I, I52 and I53, respectively. In order to adapt the controller for efiecting certain groupings of signaling aspects, the fourth arm I49 may be equipped with a pin corresponding to the pins relay N; said relays being situated below the I5I', I52 and I53; but, in the interests of clearness, such pin is omitted from Fig. 3.

As indicated by Fig. 1, portions of the arms I 49, I5I, I52 and I53 carry reference pointers or lines closely associated with indicia I50 provided upon the face of the dial I50 in order to facilitate determinations for required relative settings of said arms.

As best shown by Fig. 3, the dial I50 and arms I39, I5I, I52 and I53 are carried by the shaft H9; although the relative positionings of these and other parts along the length of said shaft are diagrammatically expanded far beyond usual practice, in order to facilitate clear representation of the various parts.

The dial I50 is fixed upon the shaft H9, and the arms Hi9, I5I, I52 and I53 are so secured to the shaft as to be capable of rotarymovement with relation thereto; said arms being frictionally driven by the rotation of said shaft with sufficient force to prevent relative displacement duringnormal operation of the mechanism, while permitting manual setting of said arms with relation to the dial I50.

The insulating cams I3I and I32 are also fixed upon the shaft II9, as is the gear I36 which meshes with the pinion I35 driven by the motor M2.

The ratio of the gearing I35, I36 between the motor M2 and the shaft I I9 is such that when the motor is operating from the intended supply source circuit, the shaft H9 will make a full revolution in a time selected for a complete signaling cycle, if operating independently of a master timer or controller; or, in a time not greater than and preferably somewhat less than an intended cycle if operating (as shown in Fig. 3) in connection with a master timer.

' The contacts 63 are so associated with the cam I 3I as to be closed during a comparatively small proportion of each revolution of the shaft H0 and to remain open at all other times; and the contacts 64 are so associated with the cam I32 as to be thereby held closed throughout each revolution of shaft II9 except a part of that portion during which the contacts 63 are closed.

A dog I54, which is fixed upon the shaft I50, extends in the path of the free ends of the pins I5I and I52; the radial distance of said pins from the shaft II9 being such that the pin I5l will pass above and the pin I52 will pass. below the dog I54. Cam surfaces are formed near the free end of the dog I54 so that as the pins I5I' and I52 are carried past said dog, said dog will be moved to turn the shaft I58 in clockwise and counter-clockwise directions, respectively.

The contact arm I51 is fixed upon the shaft I58, to be rocked in one direction or the other as the pins I 5! and I52 are carried past one side and the other of the dog I54; and the contacts 65 and 66 are so positioned that the free end of the arm I5! will engage the contact 65 while the pin I5I' is moving past the free end of the dog I54 and said contact 66 will be engaged by arm tends in the path. of the pin I53"; but does not f I I extend in the paths of the pins. I5I--an'd I52 which are situated at fless radial distances from the shaft IIQ than said pin I53. A spring I60 is I so applied as to tend to swing the arm I55 into the path of the pin I53 and the contacts 61 are so associated with the arm I55 that, during engagement of the free end of said arm by the pin I53, saidcontacts will be closed for a suitable interval, for a purpose which will be hereinafter more fully explained. q

As indicated in Fig. 4, the timer mechanism thus far described, with but little modification, will provide for controlling traffic signal lights in accordance with a pretimed cycle, where the -service requirements are extremely simple; but, in

order to meet requirements of greater complexity, more, less, or all of the supplemental equipment and wiring shown in Fig. 3 are needful.

Referring now to Fig. 4, it will be seen that the operating parts are the same as the corresponding parts indicated in Fig. 3, except that, instead of the spring l59 being so applied as to retain thev arm I51 intermediate the contacts65 and 66, as in Fig. 3, the spring I59 of Fig. 4 will tend to retain said arm ,in engagement with the one or the other'of said contacts toward which it was last moved through cooperation of the pins I5I' and I52 with the dog I54.

Associated with the traffic signal controller of Fig. 4, are the signal lamps 402 and 404; the lamp 402 giving a red or stop signal for traflic in a certain lane, and a green or go signal for trafiic in an intersecting lane; while the lamp 404 gives a green or go signal for said first named traffic lane and a red or stop signal for said intersecting lane.

The conductor 400 connects one terminal of the lamp 402 with contact 65, and the conductor 408 correspondingly connects lamp 404 with contact 06. The remaining terminals of lamps 402 and 404 are connected to supply source conductor 4l0, and supply source conductor M2 is con nected to arm I51. It will therefore be evident that when the arm I51 engages contact 65, lamp 402 will be lighted, thereby giving a go signal aspect for traffic in one lane and a stop aspect for traffic in another lane; and when the arm I51 is engaging contact 66, the opposite signaling aspects will be provided for the respective lanes.

A two-way switch comprising the arm 4M and the contacts M6 and 8, provide means whereby the controller may be adapted for operation either independently or subject to control of the contacts of a suitable master timer. Conductors 420 and 426 connect arm 4I4 with one of the contacts 64 and with supply source conductor 41?, respectively; conductor 422 connects one ofthe contacts 63 with the contact 4I8 associated with the switch arm 4I4; conductor 210 connects the remaining ones of contacts 64 and G3 with one terminal of the motor M2; and conductor 424 connects the remaining terminal of said motor with the supply source conductor 4I0.

From the foregoing it will be apparent that if the switch arm M4 is positioned upon the contact M8, the motor M2 will operate continuously; if, however, it is desired that the operation of said motor shall be rendered responsive to a master controller, having periodically operable contacts 'such as'shown at 68, the conductors 428 and 430 should beextended from such master controller contacts to the contacts 4I8 and M6, respectively, associated with the switch arm 4I4, and said arm should be positioned upon contact 4 I6.

'. The operation of a trafiic signal controlling system suchas that shown in Fig. 4, and just described, is as follows:

- Assuming that the switch arm M4 is positioned upon its associated contact 418, and that contact arm I 51 engages contactlifi, the lamp of signal 404 will be lighted, and the motor M2 will rotate the shaft I I9 until the pin I 5| engagesand moves the dog I54 so as to carry the contact arrn I51 away from the contact 66 ancl into engagement with the contact. 65; whereupon the lamp of signal 404 will be extinguished and the lamp of signal 402 will be lighted.

Thereafter, continued rotation of shaft II9 will carry pin I52 into engagement with dog I54 and thereby cause contact arm I51 to be moved away from contact 65 and into engagement with IIQ, and the division of such cycle between the period when the lamp of signal 402 is lighted and the period during which the lamp of signal 404 is lighted may be manually set, by changing the angular displacement of the arms I5I and I52.

If connections are provided for operation in connection with a master timer, and operation of such type is desired, the switch arm 0H3 should be positioned in engagement with contact 4L5, as a result of which the operation of motor M2 will be suspended whenever contacts 64 open (contacts 03 being then closed, as previously explained), unless and until the contacts 68 of the master timer are closed, whereupon actuation of the controller for another operative cycle will be initiated, as well understood by those skilled in this art.

In order to effect control of traffic signal governing lamps in a manner which will provide for conditions which are more complex than those I to which a controller such as that of Fig. 4 is suited, a circuit controlling mechanism embodying all or any needed portion of the instrumentalities of the mechanism SC indicated in Figs. 1,2, 3

and 5, should be associated with and made responsive to a timer mechanism, such as the mechanism CD.

The details of the mechanical structure of the circuit controlling mechanism SC will be best understood by referring to Fig. 2, in which an arrangement of parts is shown which corresponds generally with the disclosure of Figs. 1 and 3; but it will be noted that the solenoids E and J are shown in Fig. l as being 'both situated to the left of the cams there indicated, and in Fig. 3 as being both to the right of these cams, while in Fig. 2, in order to avoid distortion or obscuring of other parts, the solenoid E is shown to the right and the solenoid J to the left of the other parts.

The circuit controlling mechanism frame plates l5 and I6 are maintained in suitably spaced relation by the contact strips I6, I6 and 16'', which are electrically isolated therefrom by the insulating plates IT, 11. (See Fig. 1.) The frame plate I5 is secured to the panel I4 by means of the hinges 20, 20, so that the entire circuit controlling mechanism may be so swung as to carry the frame plate I6 away from the panel I 4 and thereby afford convenient access to all portions of said mechanism. The latch 2I is secured to the panel I4 for engagement with the frame plate I6, to normally maintain same in snug engagement with said panel.

The motor M3 is suitably secured to the frame plates I5 and I6, and comprises the metal disc 32, which is fixed upon the shaft 36, to drive the gear 36 through the shaft 38, ratchet wheel 40, ratchet dog 42, worm gear 44 and worm 46. The stationary magnet 52 and the adjustable magnet 54 are provided for driving the disc 32-, said magnet 54 being adjustable with relation to said magnet 52 for the purpose of varying the speed of rotation of disc 32 through manual setting of the pointer 56, which effects rotation of the pinion 58 and thereby moves the rack 60; the permanent brake magnet 62 being applied in a well-known manner.

The cam shafts I02 and I04 are driven by the gear 36, as diagrammatically indicated in Fig. 3, and as shown in greater detail in Fig. 2, where the gears I06 and I08 are fixed upon the shaft I02, and the gear H0 is fixed upon the shaft I04; the gear I06 being engaged by the gear 36 and the gear I08 acting through the gear I ID to drive the shaft I04 at the speed of the shaft I02.

The cams 20I, 202, 203, 204, 205, 206, 201, 208, 209, 2I0, 2| I, 2I2, 2I3 and 2 are mounted upon the shaft I04 to be driven thereby, in a manner facilitating wide variations in the relative settings and periods of effectiveness thereof, as hereinafter more fully explained, in connection with Figs. 5 and 6.

G The cams 2II, 2I8, 22I, 222, 223, 224 and 225 are correspondingly secured to shaft I02.

The contact finger 20I' is operatively associated with the cam 20I. Said finger being mounted upon an insulating strip I0, carried by the arm I2, which is, in turn, pivoted upon the rod I4. The free end of the contact finger MI is situated adjacent the contact strip I6, and so that intended movement will effect closing and breaking of an electrical connection therebetween. The spring I8 is so applied to the arm I2 as to urge movement of the finger 20I' toward the strip I6. A follower 80, pivoted at 82, carries a roller 84 near the free end thereof, which roller rides the cam 20I, and the thrust rod 86 connects the follower with the arm I2 so that the rise of the cam 20[ will cause the finger 20f to be moved away from the strip 16, and withdrawal of the raised portion of the cam 20I from the path of the roller 84 will permit the spring I8 to move the contact finger 20I' into electrical connection with the strip I6. The contact fingers 202', 203, 204', 205',.206, 201', 208, 209', 2I0, 2II, 2I2', 2I3 and 2M being correspondingly associated with the cams 202, 203, 204, 205, 206, 201, 208, 209, 2I0, 2II, 2I2, 2I3 and 2M, respectively, and the fingers 209" and 2I I" being similarly associated with the fingers 209 and 2| I', respectively, so as to move therewith. The fingers 209" and 2H" cooperate with the contact strip "I6", and the contact fingers 202', 204, 206, 208', 2I0', 2I2' and 2I4' correspondingly cooperate with the contact strip I6, while the remaining ones of the aforesaid contact fingers cooperate with the strip I6. The contact fingers 20I, 203', 205', 201', 209, 2H and M3 are carried by the rod I4, while the contact fingers 202, 204', 206', 208', 2H), 2I2 and 2" are carried by the rod 14.

The follower 80' is arranged for cooperation with the cam 2| 8 in a manner corresponding to that heretofore described in connection with follower 80, said follower being pivoted on the rod 82', and carrying the insulating strip I0 to which is secured the contact finger 2I8'. The contact strip 16 is mounted in cooperative relationship with the finger 2I8, and the spring 18' is so applied to said finger that when the teeth of the cam 2I8 are not in effective relationship with the follower 80, the spring 18 will move the finger 2I8' into engagement with the contact strip 70". The contact fingers 2II, 225, 223, 222', 22I and 224' are correspondingly mounted and associated with said contact strip and with the cams 2I'I, 225, 223, 222, HI and 224, respectively.

It will be noted that, in the interests of clearness and simplicity, the representations of the various cams and their associated contacts in the diagrammatic representations thereof in Fig. 3 differ somewhat from the more specific representation of the form and arrangement of these parts in Fig. 2; correspondingly, the cooperating contact tips indicated in the more or less expanded isometric view of Fig. 2, correspondingly differ, for like reasons, from the proportions as more accurately portrayed by Fig. 1. Likewise, Fig. 13 is merely illustrative of the various electrical circuits and no attempt is made to illustrate the parts in a mechanically operable form.

The rock shaft I62 is connected through the arm I64 and link I66 to the core I68 of the solenoid J, a spring II0 being so applied to the arm I64 as to tend to move same in the direction which will withdraw the core I68 from the coil of the solenoid J, and the stop pins I72 and I'M are positioned in the path of movement of the arm I64 so that said pin I12 will limit the movement of the arm I 64 in response to the spring I10, and said pin I14 will limit the movement of said arm in response to the pull of the core I66.

The arrangement of parts is such that upon effective energization of the solenoid J, the rock shaft I62 will be rotated in one direction approximately and, thereafter, upon deenergization of said solenoid, said shaft will be rocked to a like extent in the opposite direction.

The portions of the rock shaft I62 which are situatedin the paths of the insulating strips I0 associated with the contact fingers 203' and 2H are so cut away that, when the shaft is in the position which it occupies when solenoid J is deenergized, and the arm I64 is resting against the pin I12, said cut away portions will permit their associated contact fingers to move into engagement with the contact strips 16, but when solenoid J is energized, and said arm I64 has been moved into engagement with the stop pin I14, such cut away portions will be so moved with relation to the respective insulating strips that their associated contact fingers will be held in spaced relationship from the contact strip 16.

Portions of the rock shaft I62 which are situated in the paths of the insulating strips 18 associated with the contact fingers 28 I 285, 289' and 2I3, are correspondingly cut away, except that the portions associated with the last named contact fingers are so angularly positioned upon the shaft as to permit their associated contact fingers to be brought into connection with the contact strip 16- only while said shaft is in the position which it occupies when the arm I64 has been moved into engagement with the stop pin I14. The insulating strip 18 associated with contact finger 281' is so formed as to permit said contact finger to move into connection with the contact strip 16 irrespective of the positioning of said shaft I62.

From the foregoing, it will be apparent that so long as the solenoid J remains deenergized, the rock shaft I62 will be so positioned as to prevent contact fingers 28i', 285, 208', 288 and 2I3' from establishing connectionswith contact strip16, while permitting (subject to the positioning of their associated cams) contact fingers 283,, 281, 2H and 2H" to connect with their cooperating contact strips; and so that,

when said shaft I62 has been rotated responsive to energization of solenoid J, contact fingers 28I', 285', 289', 289" and 2I3' will be permitted (subject to the positioning of their associated cams) to move into connection with their cooperating contact strips while corresponding connections will be prevented as to contact fingers 283', Hi and 2H.

Each of the cam followers 88 carries, at the free end thereof, a projection 88" for cooperation with the half-round rock shaft I16; the relative formation of the parts being such that when the flattened portion of said shaft is disposed in plane parallel of said projections 88", said followers will be permitted to move in accordance with the contours of their respectively associated cams, and so that when said shaft has been suitably rotated, said followers will be supported so as to prevent such movement thereof as would permit their respectively associated contact fingers from moving into connecting relationship with their cooperating contact strips. Theshaft I16 has fixed thereon an arm I64 which is connected through the link I66 to the core I68 of the solenoid E. Stop pins I12 and I14 are provided for limiting the angular movement of said arm I64, and the spring I18 is applied for urging movement of said arm in the direction opposite to' that imparted thereto by excitation of the solenoid E, so that the rock shaft I16 will be subject to actuation by the solenoid E in a manner corresponding to the actuation of v the rock shaft I62 by the solenoid J as hereinbefore described.

As most clearly shown in Fig. 3, the pedestrian memory relay P comprises the stationary contacts 22 and 24 and the contacts 26 and 28 movable responsive to energization of said relay into engagement with said respective stationary contacts.

The flashingservice control relay N comprises the stationary contacts III, H2, H4 and H6 and the movable contacts H3, H5 and H1. Upon energization of said relay, the contact H3 is movable into engagement with contacts III and H2, the contact H5 is movable into engagement with contact H4, and the contact H1 is movable away from contact H6.

In order to more clearly indicate the application of the traffic signal controlling mechanism thus far described to a group of traiiic signal lamps, and a group of traffic responsive contacts, there is shown at S, in a conventionally diagrammatic manner, the green (G, G, G, G), amber (A, A, A, A) and red (R, R, R, R) traffic signal lamps for governing trafiic in an arterial highway and an intersecting highway; the "right-turn-indicating lamps 48 and 58 being associated with the lamp groups provided for the main or arterial highway. As representative of traffic responsive contacts; the four pedestrian push buttons B, B, B, B are indicated as if at respective corners of the intersection.

There is also indicated at T a master timer comprising an electric motor MI, a cam 238 rotated by said motor through the reduction gears 232 and 234, for maintaining the contacts 236 in separated relationship during all but a comparativelysmall portion of a cycle of the rotation of said cam; an adjustableresistance 238 being provided for varying the speed of the motor MI, an adjustable resistance 248 for regulating. the speed of the motor or motors of local trafiic signal controllers, such as the motor M2, and switches 242 and 253 for suspending the normal routine cycle of response of the signal lamps to the rotation of the cams of the signal circuit controlling mechanism SC and, in one instance, substituting therefor an intermittent or flashing amber aspect, as will be hereinafter more fully explained.

The electrical connections between the parts vthus far described are as follows:

Ihe supply source conductor 258 connects with the conductors 252 and 254, and the supply source conductor 256 connects with the conductor 258 and one terminal of the adjustable resistance 238. The conductor 252 extends from supply source conductor 258 to one terminal of the magnet of relay N, and the conductor 260 connects the conductor 252 to one terminal of the motor M2. The conductor 254 connects one terminal of the motor MI to conductor 258 and conductor 262 connects the other terminal of said motor MI to the remaining terminal of the adjustable resistance 238. The conductor 258 connects supply conductor 256 through closed switch 253 to contacts H1 of relay N, the conductor 264 serially includes the, switch 242 and connects the conductor 258 with the other terminal of the magnet of relay N; the conductor 266 connects the conductor 256 to one of the contacts 236 and the other of said contacts is connected through conductor 268 with one of the contacts 63; the other of said contacts 63 being connected through the conductor 218 with the remaining terminal of the motor M2 and with one of the contacts 64. The other of said contacts 64 is connected through the conductor 212 to one terminal of the adjustable resistance 248 at the master timerT, the other terminal of said resistance being connected to conductor 258.

Conductors 214, 216 and 218 connect the stationary members of contacts 66, 85 and 61 with contact fingers 222', HP and 223'. respectively.

The conductor 280 extends from contact arm I51 to one terminal of motor M3 serially including adjustable resistance 282. The remaining one of the'contacts 61, and the contact fingers 224' and 225' are also connected to said conductor 280. The conductor 284 connects conductor 280 with the contact N4 of relay N, and the conductor 286 connects the contact strip 16' with the contact strip 16'. The conductor 288 connects the contact strip 16' with the contact strip 16; the conductor 296 connects the contact strip 16 with the contact strip 16"; the conductor 230 connects the contact finger 2i8' with the contact 3 of relay N, and the conductor 282, which serially includes the switch 284, connects the conductor 230 with the contact finger 2H.

The supply source conductors 300 and 302 may derive energy from the same source as the supply source conductors 250 and 256, or from a different source, as may be in any instance more convenient.

The supply source conductor 300 connects with one terminal of each of the signal lamps R, R, R, R; A, A, A, A; G, G, G, G; 48 and 50; the conductor 304 connects the conductor 300 with the remaining terminal of the motor M3, the switch 306 being serially included in said conductor in close proximity to this motor; and the conductor 308 connects the conductor 304 with an end of the winding of solenoid J. The conductor 3l0 connects one terminal of the winding of relay P to the supply source conductor 300, and the conductor 3l2 connects the other terminal of said winding to the contact 28; said other terminal being also connected through the conductor 314 to the conductor 3I6 which connects to one terminal of each of the pedestrian push buttons B, B, B, B; the remaining terminals of said buttons being interconnected by the conductor 3? which is, in turn, connected through the conductor 320 with the supply source conductor 302.

The supplyisource conductor 302 extends to the contact strip 16, and the conductor 322 connects said conductor 302 with the contact H5 of relay N. The conductor 324 connects the contact finger 20l with one terminal of each of the stop lamps R, R provided for the arterial highway at S, and the conductor 326 connects the' contact finger 202 with the conductor 324. The contact'fingers 203' and 204' are correspondingly connected through conductors 328 and 330 with the green go lamps for said arterial highway. correspondingly alternative current paths are provided from the amber lamps A, A for the arterial highway to the contact III of relay N and to the contact fingers 205', 201' and 209" through conductors 334, 336 and 338. The conductor 340 connects the contact finger 206 with the remaining terminals of the go signal lamps G, G for the intersecting highway. The conductor 342 connects the contact finger 208' with the remaining'terminals of the stop lamps R, R for the intersecting highway. The conductor 344 connects the remaining terminals of the caution or amber lamps A, A, for the intersecting highway, with the contact finger 209' and with the contact H2 of relay N. The conductor 345 connects the contact finger 2Hf' with the contact 24 of relay P, and the conductor 346 connects the conductor344 with the contact finger 2l0'. The conductor 348 connects the contact finger 2| I with the remaining terminals of the rightturn arrow lamps 48 and 50, and the conductor 350 connects the contact finger 2 l4 with the conductor 348. The conductors 352 and 354 connect the contact fingers 2 I 2 and 2 l3 with the contacts 22 and 26 of the relay P, respectively; and the conductor 356 connects the remaining end of the winding of thesolenoid J with the conductor 354. The conductor 358 connects one end of the winding of the solenoid E with the conductor 252, and the remaining end of said winding is connected through the conductor 360 to the contact 6 of relay N.

When the various parts are positioned as shown in Fig. 3, current flow is efiective through paths as follows:

From the supply source conductor 250, through conductor 254, motor Ml, conductor 262 and adjustable resistance 238 to supply source conductor 256; thus causing the motor Ml to drive the cam 230 at desired speed, as determined by the adjustment of the resistance 238.

From the supply source conductor 250, another current path is effective through conductor 252 to as may be determined by the adjustment of the resistance 240, at the master timer '1.

Still another current path is established from the supply source conductor 250, through conductors 252 and 358, to and through the winding of the solenoid E, thence through conductor 360, contacts H6 and Ill, and conductor 258,

including closed switch 253, to the supply source conductor 256, i

From the supply source conductor 300, a current path is established through conductor 304, closed switch 306, motor M3, adjustable resistance 282, conductor 280, contact finger 224, contact strip 16", conductor 286, contact strip 16', conductor 288, and contact strip 16, to the supply source conductor 302, thuscausing the motor M3 to drive the cam shafts l02'and I 04 at such speed as is determined by the manual adjustment of the resistance 282.

For effecting the display of the right-turn signal by lighting the lamps 48 and 50, a current path is established from the supply source conductor 302, through contact strip 16, thence through parallel current paths one of which is through the contact finger 2| I to conductor 348 and the other of which comprises conductor 288, contact strip 16', contact finger 2 l4 and conductor 350 to said conductor 348, thence through said lamps in parallel to the supply source conductor 300.

The red stop lamps R, R for the intersectinghighway, are lighted. through a current path extending from the supply source conductor 302,

through contact strip 16, finger 208', conductor amaees tact finger 204' and conductor 330 to said conductor 320, thence through said lamps in parallel to the supply source conductor 300.

Because of the establishment of the foregoing current paths, the motor MI will operate at a speed as determined by resistance 238; the motor M2 will operate at a speed as determined'by resistance 240; the motor M3 will operate at a speed as determined by resistance 282; the rock shaft I16 will be positioned, responsive to the energization of the solenoid E, so as to permit movement of the contact fingers which are functionally associated therewith, in accordance with the contours of their respective cams; the rock shaft I62 will be positioned, due to non-energiza- 'tion of the solenoid J, so as to permit the con- H4 and the contact III will engage the contact.

H6; therelay P will be deenergized so that its contacts 26 and 20 will be separated from the contacts 22 and 24, respectively; the right-turn lamps 48 and 50, and the green "go lamps G, G for the arterial highway will be lighted, as will be the red "stop lamp R, R fortheintersecting highway; and the traflic responsive contacts B, B; B, B will stand open.

In order to provide intended operative results, the adjustment of the resistance 282 should be such that the motor M3 will effect an intended cycle 'of movement (which, "with the arrangement shown, would be one revolution of the cam shafts I02 and' I04) in a time somewhat less than any intended cycle of rotation of the shaft H9, for a reason which will be hereinafter more fully explained.

Correspondingly, the resistance 240 should at all times be so adjusted that the motors M2 of all of the local traffic signal controllers which are arranged in responsive relationship to the master timer T shall move through their. intended operating cycle in a time not greater than-,and preferably somewhat less than-that of the operating cycle of the cam 230 of said master timer.

The adjustable arms I49, I5I, I52 and I53 should be so relatively set as to provide desired relative characteristics of the various signal cycle component .periods'as will be hereinafter more fully explained. The switch 242 should stand open and the switches 253 and-306 should stand closed.

Assuming that all parts have been suitably adjusted and set, as just pointed out, the operation of the apparatus and system indicated by Fig. 3 will be as follows: operation of motor M3 will cause rotation of shafts I02 and I04 until the raised portion of earn 225 is'withdrawn, permitting contact finger 225 to move intoconnection with strip 16", thus providing a current path in parallel with that rendered effective by connection of contact finger 224' with said strip;

thereafter, theensuing-rotation of shaft I02 will cause the raised portion of earn 224 to move contact finger 224' away from contact strips 16", whereupon, the further rotation of shaft I02 will bring another raised portion of cam 225 into engagement with contact finger 225, so as to move same away from strip 16" and thus interrupt the energizing current path for motor M3, causing same to come to rest.

1 During the rotation of the shaft I02 and I04 just referred to, and at the time of (or, preferably slightly before) such separation of contact 225' from strip 16", the raised portion of cam 22I will be withdrawn so as to permit contact finger 22I to move into connection with strip 16", thus making provision for re-establishment of a driving current path for said motor M3, responsive to rotation of shaft H9 of timer mechanism CD.

During the signal periods rendered effective, incidental to activities of the signal circuit controlling mechanism SC thus far described,--the activities of the timer mechanism CD and of .the master timer T include the following:

The motor M2 continued to drive the shaft'HS in clockwise direction, as viewed in Fig. 3, until the raisedportion of cam I 3| had effected closure of contacts 63, and the raisedportion of cam I32 had, immediately thereafter been withdrawn so as to permit separation of contacts 64. Motor MI of master timer T would, at this time, have rotated cam 230 a sufiicient distance to nearly or quite withdraw the raised portion thereof, so that at or soon after attainment of the stage of the operative cycle of the circuit controlling mechanism CD just referred to, the contacts 236 will be permitted to close; so that, upon interruption of the previously described current supply path for motor M2 due to separation of contacts 64, an alternative current path will be prov ded from conductor 250, through conductors 252 and 260, through motor M2, conductor 210, contacts 63, conductor 268. contacts 236, conductors 266 and 258 (including switch 253) 'to supply source conductor 256, in the event that contacts 236 had then been permitted to close.

If. at the time when contacts 64 pen, as just referred to. the cam 230 has not yet permitted contacts 236 to close, motor M2 will be brought to rest until such time as contacts 236 next close.

From the foregoing, it will be evident that such local controllers as are associated with the master timer T. in a manner such as indicated in Fig. 3, will be kept in step or in desired cyclic relat on with one another through the synchronizin effect of said master timer.

During the ensuing rotation of shaft H0, cam I32 wi lnext close contacts 64. and thereby establish the prev ously described supply current path for motor M2. and the raised portion of cam I3 will be withdrawn so as to permit contacts 63 to again open.

The ensuing rotation of shaft H9 by motor M2 w ll cause p n II' to be carried into engagement with dog I54. swinging same so as to carry contact arm I51 into enga ement with contact 65: thus estab ish imz a driving current path for restarting motor M3 as follows: from supply source conductor 00. through conduct r 3M and swi ch 336 to one terminal of motor M3, through sa d motor and its associated resistance 282. t rough conduc or 280, contact arm I51, contact driving motor M3 will thus be supplied until the r 05 65. c nductor 216. contact finger 22I', contact next raised portion of cam 225 engages contact finger 225', irrespective of continued engagement of contact 65 by contact arm I51 of timer mechanism CD.

In the course of the rotation of shaft I02, prior to the engagement of contact finger 225 by such next raised portion of cam 225, as just referred to, cam 204 will cause contact finger 204 to move away from contact strip 16', and thus interrupt one of the two parallel current paths provided for the current supply to the green go lamps G, G for the arterial highway; but, inasmuch as contact finger 203 in the other one of the parallel paths remains closed, such lamps will continue to burn.

At or about the time that contact finger 204 is thus raised, cam 2I2 will momentarily permit contact finger 2I2 to move into connection with contact strip 16 for a purpose which will be hereinafter more fully explained. Further rotation of shaft I02 will cause cam 2 I4 to lift contact finger 2I4 away from contact strip 16', thus breaking one of the parallel paths through which current is supplied to the green arrow lamps 48 and 50; but inasmuch as the other parallel current path through contact finger 2II' remains closed, these lamps will, at this time, continue to burn. Following the accomplishment of the foregoing results, continued rotation of shaft I02 will withdraw the raised portion of cam 222, so as to permit contact finger 222 to move into connection with contact strip 16"; and, thereafter, such next raised portion of cam 225 will lift contact finger 225 away from contact strip 16", and thus again bring motor M3 to rest.

During the ensuing rotation of shaft II9, the pin I52 is carried into engagement with the dog I54, swinging same so as to carry contact arm I51 into engagement with contact 66, thereby establishing a driving current path for motor M3 from supply source conductor 300, through conductor 304 and closed switch 306 to and through motor M3 and its associated resistance 282. through conductor 280, contact arm I51, contact 66, conductor 214, contact finger 222, contact strip 16', conductor 286, contact strip 16', conductor 288, and contact strip 16 to supply source conductor 302.

As a result of establishment of such current path, motor M3 will rotate shaft I02 and thereby remove the raised portion of cam 225 permitting contact finger 225 to move into engagement with contact strip 16" and thereby provide for supplying driving current for motor M3 until the next raised portion of cam 225 engages contact finger 225, irrespective of continued engagement of contact 66 by contact arm I51 of timer mechanism CD.

During the rotation of shaft I02, just referred to, shaft I04 will be so turned as to withdraw the raised portion of cam 201 and thereby permit contact finger 201 to connect with contact strip 16, thus establishing a current path for lighting the arterial highway amber lamps A, A from supply source conductor 302 through contact strip 16, contact finger 201', conductors 336 and 334 and said lamps in parallel to supply source conductor 300.

Movement of shaft I04, such as thus far described, will also cause the raised portion of cam 203 to move contact finger 203' away from contact strip 16 and thereby effect extinguishment of the green go. lamps G, G for the arterial highway, by interrupting the current path through which they had been lighted, as hereinbefore more fully explained.

The rotation of shaft I04 then ensuing will cause cams 202, 206 and 2I4 to permit their associated contact fingers 202', 266' and 2I4', respectively, to close, and cams 201 and 208 to lift their associated contact fingers 201 and 208', respectively; all of which changes will occur at or about the same time.

When contact finger 202' thus moves into engagement with strip 16', the red stop lamps R, R for the arterial highway will be lighted through a current path from supply source conductor 302, through contact strip 16, conductor 288, contact strip 16', contact finger 202', conductors 326 and 324, and said lamps inv parallel, to supply source conductor 300.

When contact finger 206' connects with contact strip 16, as just referred to, the green go lamps G, G for the intersecting highway will be lighted through a current path from supply v source conductor 302, through contact strip 16,

conductor 288, contact strip 16 contact finger 206', conductor 340, through said lamps in parallel, to supply source conductor 300.

When contact finger 2I4' thus connects with contact strip 16, the parallel path is restored through which current had been supplied to the green arrow lamps 48 and 50.

The withdrawal of contact fingers 201' and 208 from'contact strips 16 and 16', respectively, as just described, resulted in opening the current paths previously effective therethrough, and thus resulted in extinguishment of the amber lamps A, A for the arterial highway and the red stop lamps R, R for the intersecting highway.

Following the accomplishment of the foregoing results, the ensuing 'iotation of shaft I02 will withdraw the raised portion of cam 223 so as to permit contact finger 223' to move into connection with contact strip 16"; and, thereafter, the next raised portion of cam 225 will lift contact finger 225' away from contact strip 16", and thus again bring motor M3 to rest.

During the rotation of shaft I I9 following actuation of dog I54 by pin I52, the pin I53 is ,carried into engagement with the arm I55, swinging same about shaft I56 so as to close contacts 61 and thereby establish a driving current path for motor M3 from supply source conductor 300, through conductor 304-and closed switch 306, through motor M3 and its associated resistance 282, through conductor 280, contact 61, conductor 218, contact finger 223', contact strip 16", conductor 286, contact strip 16', conductor 286, and contact strip 16 to supply source conductor 302. c

As a result of the establishment of such current path, the motor M3 will rotate the shaft I 02 and thereby remove the raised portion of cam 225, thus permitting contact finger 225' to move into connection with contact strip 16". Current for driving motor M3 will be thus supplied through the path just traced until the next raised portion of cam 225 engages contact finger 225, irrespective of continued closure of contacts 61 of the timer mechanism CD. 'When the raised portion of cam 225 has engaged the contact finger 225', the parts of Fig. 3 will be positioned as therein shown; the shafts I02 and I04 having completed one cycle of normal operation.

In the course of the rotation of the shaft I02 prior to the engagement of the contact finger 225' by the next raised portion of cam 225, as just referred to,'cam 206 will cause contact-finger 206' to move away from contact strip 16, theresupplying the green go lamps G, G for the intersecting highway.

Simultaneously with the separation of contact finger 206 from contact strip 16, the raised portion of cam 2I0 will be withdrawn so as to permit connection between contact finger 2") and contact strip 76, thus establishing a current path for lighting the intersecting highway amber lamps A, A from supply source conductor 302, through contact strip 16, conductor 288, contact strip I6, contact finger 2I0', conductors 346 and 344, and through said lamps in parallel, to supply source conductor 300.

Continued rotation of shaft I04 will next cause the raised portion of cam 2I0 to move contact finger 2I0 away from contact strip I6 and thereby effect extinguishment of the amber lamps A, A, of the intersecting highway.

Simultaneously with the separation of contact finger 2I0 from contact strip I6, the raised portion of cam 202 will cause contact finger 202 to move away from contact strip 16' and thereby cause extinguishment of the red stop lamps R, R for the arterial highway; and, the raised portions of cams 203, 204 and 208 will be withdrawn, thus permitting contact fingers 203', 204 and 208' to connect with their respectively associated contact strips.

When contact fingers 203' and 204' thus move into connection with contact strips I6 and 16', respectively, the green go lamps G, G for the arterial highway will be again lighted through parallel current paths comprising conductors 328 and 330, as hereinbefore more fully explained.

Correspondingly, when contact finger 208' thus moves into connection with contact strip 16, the red stop lamps R, R for the intersecting highway will be lighted through a current path including conductor 342.

Throughout the cycle of normal operation for shafts I02 and I04 as just completed, contact fingers 2M, 205', 209', 209"and 2I3' are maintained out of efiective engagement with their associated contact strip 16, throughpositioning of rock shaft I 62 resultant from deenergization of solenoid J.

If, at any time in the cycle, one of the pedestrian push buttons B, B, B, B is closed, pedestrian memory relay P will be energized, through a current path from supply source conductor 302, through conductors 320 and 3I8, through the closed push button, through conductors 3I6 and 3! 4, through winding of relay P and conductor 3| 0. to supply source conductor 300. Upon establishment of this current path, contacts 26 and 28 will be brought into engagement with contacts 22 and 24, respectively. Such engagement of contact 24 by contact 28 establishes a holding path from supply source conductor 302, through contact strip I6, conductor 296, contact strip 16",

contact finger 2! I", conductor 345, contacts 24 and 28, conductor 3| 2, winding of relay P and conductor M0 to supply source conductor 300.

Following energization of relay P, as just referred to, the cycle of control of the highway signal lamps at S will continue, as hereinbefore more fully explained, until the raised portion of cam 212 is withdrawn, thereby permitting contact finger 2 I2 to move into connection with contact strip 16; whereupon a current path for energization of solenoid J will be established from supply source conductor 302, through contact strip I6, conductor 288, contact strip 76', contact finger 2I2', conductor 352, contacts 22 and 26, conductors 354 and 356, winding of solenoid J, and conductors 308 and 304 to supply source conductor 300.

When the solenoid J is thus energized, rock shaft I62 will be so rotated as to permit contact finger2 I3 to move into connection with contact strip I6, and, thereupon, to move contact fingers 2H and 2H away from contact strips I6 and 16'', respectively.

Such engagement of contact strip I6 by contact finger 2 I3 provides a lock-up path for solenoid J which is exclusive of contact finger 2I2' and contacts 22 and 26, as follows: from supply source conductor 302 through contact strip '16, contact finger 2I3', conductors 354 and 356, winding of solenoid J, conductors 308 and 304 to supply source conductor 300. Such separation of contact finger 2II" from contact strip 16" breaks the holding path for relay P, as hereinbefore described, resulting in its deenergization and in separation of contacts 26 and 28 from contacts 22 and 24, respectively.

From the foregoing, it will be evident that the parts should be so adjusted and related that contact finger 2I3' will connect with contact strip I6 before contact 26 moves away from contact 22, following interruption of the energizing current path of relay P.

A further result of the rotation of rock shaft I62 which is incidental to energization of solenoid J, is the presentation of cut away portions of said shaft so as to permit contact fingers 20I, 205, 209' and 209 and, as already referred to, contact finger 2l3, to move into connection with their associated contact strips I6 and 16" whenever permitted so to do by their respectively associated cams; and such movement of said rock shaft further withdraws cut away portions thereof so as to provide support, independent of their associated cams, for contact finger 203', in addition to the support of contact fingers H I and 2I I" previously referred to.

When rock shaft I62 has been thus rotated, the

raised portions of cams 20l and 209 will prevent their respectively associated contact fingers from moving into connection with their cooperating contact strips, but the raised portion of cam 205 will be then withdrawn so that contact finger 205' will immediately move into engagement with contact strip i6, and the samewill be true with respect to cam 2l3 and contact 2I3, as already mentioned. At the same time, cam 204 will move contact finger 204 away from contact strip 16', thus effecting extinguishment of the green go lamps G, G for the arterial highway.

The connection of contact finger 205 with contact strip I6, just referred to, establishes a current path for lighting the amber lamps A, A for the arterial highway from supply source conductor 302, through contact strip T6, contact finger 205', conductor 334, and said lamps in parallel, to the supply source conductor 300.

From the foregoing, it will be apparent that, at or immediately after rotation of rock shaft I62 responsive to energization of solenoid J, righthand arrow signal lamps and and amber lamps A, A for the arterial highway, and red "stop lamps R, R for the intersecting highway will be lighted.

Ensuing rotation of cam shaft I04 will next withdraw raised portions of cams 20! and 209, thus permitting their associated contact fingers 20I and 209 to move into connection with their associated contact strip I6. Contact finger 20I' thus establishes a current path for red "stop" lamps R, R for the arterial highway, from supply source conductor 302 through contact strip I6, contact finger 20I', conductor 324, and said lamps in parallel, to supply source conductor 300; and contact finger 209 thus establishes a current path for amber lamps A, A for the intersecting highway from supply source conductor 302, through contact strip I6, contact finger 209, conductor 344 and said lamps in parallel to supply source conductor 300.

At or about the time that contact fingers 20I' and 209' are permitted to connect with contact strip I6, as just described, the raised portion of cam 2I4 moves contact finger 2I4' away from contact strip I6, thus interrupting the second one of the parallel paths through which rightturn arrow lamps 48 and 50 had been previously lighted, thereby effecting the extinguishment of said lamps. (The other parallel path having been interrupted when contact finger 2 I I was moved away from contact strip I6 by rock shaft I62.)

From the foregoing it will be seen that the right-turn arrow lamps 48 and 50 and all of the green go lamps G, G, G, G will now be extinguished, and that the red stop lamps R, R, R, R and the amber lamps A, A, A, A for both highways will now be lighted; thus providing a signaling aspect the presentation of which constitutes what may be termed a pedestrian period, by indicating that all vehicular movements into, around or across the intersection shall cease, and that pedestrian movements may freely proceed within the area of the intersection.

Following accomplishment of the results just described, shafts I02 and I04 will be rotated so as to cause one of the raised portions of cam 225 to lift contact finger 225', thus discontinuing the current supply for motor M3 unless and until such supply is continued or resumed through the operation of timer mechanism CD, whereupon current supply for said motor M3 will be re-' stored and rotation of the shafts I02 and I04 will proceed as hereinbefore more fully explained.

Such continuing rotation of shaft I04 will, at or about the same time, withdraw raised portions of cams 202, 206 and 2I4 and will present raised portions of cams 205, 201, 208, 209 and 2I3; although the presentation of the raised portion of said cam 2 I3 will be but momentary in character.

As a result of the cam actions jus'. described, contact finger 2I3 wil. be moved away from contact strip I6, thereby interrupting the current path previously described for energization of solenoid J, whereupon rock shaft I62 will be rotated to its normal position by the urge of spring I10, thereby withdrawing the cut away portions thereof so as to render unresponsive to their respective cams the contact fingers 20I', 205, 209' and 2I3; while rendering responsive to their respective cams the contact fingers 203', 2| I' and 2H".

Resultant from restoration to normal position of rock shaft I62, and to the movement of the various cams as just referred to, contact fingers 20I, 205, 208' and 209' will move to open circuit position, thereby interrupting the current paths previously effective therethrough; thus terminating the pedestrian period. Contact fingers 202, 206 and 2I4' will, at the same time, be permitted. by the contour of their respectively associated cams, to move to closed circuit position, thereby establishing the current paths controlled thereby. In this connection it will be noted that, although rotation of rock shaft I62 to restored position brought a cut away portion thereof in effective relation to contact finger 203', the cam associated with this contact finger prevented its immediate closure.

From the foregoing it will be seen that the right-turn arrow lamps 48 and 50, and the green go lamps G, G for the intersecting highway, will be lighted, and that the red stop lamps R, R for the arterial highway will continue to burn because the newly established path through contact finger 202 serves as a substitute for the interrupted path through 'contact finger 20I.

From this point on, the operative cycle of the parts Will continue as in the normal or nonpedestrian period cycle hereinbefore more fully described.

In instances where one of the push buttons B, B, B, B is initially actuated at a stage in the cycle subsequent to movement of contact finger 2I2' to closed circuit position, relay P will energize and be maintained in locked-up condition until said contact finger moves to closed position in the course of the next succeeding cycle. A so-called memory feature is thus provided as to such actuation of any of said push buttons as may occur; to the end that, when the system has been displaying a cycle or cycles of signal periods not including a pedestrian period, operation of any one of the push buttons B, B, B, B will cause the system to effect a cycle of operation including a full pedestrian period upon the next occasion when it is possible for it to properly do so. On the other hand, operation of any of such push buttons during that portion of a pedestrian period in which pedestrian movement is permitted in the intersection, will not re-- sult in the relay P being left locked up; and therefore will not cause a repetition of the pedestrian cycle, because the locking current path for this relay is now interrupted at contact finger 2I I"; in fact, it is evident that the operation of any of such push buttons B, B, B, B at a time when relay P is in locked-up condition, or during energization of solenoid J resultant from any previous energization of relay P, will not result in establishment of a cycle having a pedestrian period, supplemental to the cycle already or about to be rendered effective.

From the preceding description of a cycle comprising normal traffic periods, and which may therefore be termed a normal cycle, and a cycle comprising a pedestrian period (and which may therefore be termed a pedestrian cycle) it will be apparent that stop and go periods are provided for the arterial highway and for the intersecting highway, by both of these types of cycles; but, in the instance of the pedestrian cycle, the go period for the arterial highway is shortened, and a pedestrian period" is added, which occupies the time deducted from the normal arterial go period.

The characteristics of operating cycles, under settings and operations as hereinbefore more fully described, are graphically indicated by the chart of Fig. '7, as to a normal cycle which does not include a pedestrian period, and in Fig. 8 as to a pedestrian cycle which does include such a period.

The representation of a normal cycle in Fig. 7 includes three stripes in the upper portion thereof, the first of which is lined to represent the lighting of the green or go lamp for the arterial impending change fromgo"tostop (such amber periods being sometimes termed clear or clearing periods) and the third stripe is lined to represent the lighting of the red or stop lamp for the arterial highway. Associated with these three stripes is an indication representative 'of the continuous effectiveness of the right-turn green arrow signal.

In the lower portion of this chart, there are three stripes which correspondingly indicate the concurrently effective go, clear and stop signal aspects for the intersecting highway.

The representation of a pedestrian cycle in the chart of Fig. 8 correspondingly indicates, in the upper portion thereof, the signal aspects .afiecting the arterial highway, and, in the lower portion, those affecting the intersecting highway.

With the various portions of the equipment set and adjusted as hereinbefore more fully described, should -it be desired to, upon any occasion, increase the time allotted-to the display of the green lamp or go signal for the arterial highway, without altering the duration of any of the other periods, it is evident that the entire cycle length. should be increased to the desired extent; and, to this end, the resistance 238 should be so adjusted that the time required for one revolution of the cam 230 will be increased to the extent to which it is desired to increase the time occupied by the total cycle as well as that occupied by that portion of the cycle which is allotted for traflic movement on the arterial highway.

If it. is desired to increase the times allotted to the intersecting highway green lamp or go signal period as well as to the pedestrian period, without appreciably altering the time allotted to the arterial highway green light or go period effective during a pedestrian cycle,- the resistance 240 and 238 should both be adjusted so that the intervals required for a revolution of the shaft 6 I9 and for that of the cam 230, respectively, would be increased to a suitable extent; provided there had been previously effected a suitable relative setting of arms |l and IE3.

If it is desired to increase the arterial highway go period, the intersecting highway go" period and the pedestrian period (when in effect), the resistance 240 should be adjusted so as to retard the rate of movement of the shaft H9, to

the extent required to give the added time for i the intersecting highway go and the pedestrian periods, and the resistance 238 should be adjusted to retard the rotation of the cam 230 to an extent corresponding to the retardation of the shaft H9, in addition to retardation representative of the amount of extension desired for the arterial highway go period. Thus, if the increase in time desired other than for the arterial highway is 10 seconds and that desired for the arterial highway is seconds, the time required for one revolution of the cam 230 should be in creased seconds.

If it is desired to decrease the durations of the periods just referred to, this can be accomplished by corresponding adjustments, of the resistances 238 and 240 in the opposite direction; subject,

lengths of other periods.

the adjustment of resistance 238 could be such that every other closure of contact 236 would occur during an open circuit period of contact 63, to the end that, when the master timer T drives the cam 23!! at a speed which would give one rotation of said cam in substantially less time than that occupied by one revolution of the shaft H9 of the timer mechanism CD, the effect would be substantially the same as if the cam 23!] were being rotated at one-half the speed.

It will also be noted that the changes in operating characteristics thus far described are based upon an assumption that the duration of the amber so -called change or clearing periods would be unaffected by changes in the Such an arrangement is considered desirable, under most circumstances, inasmuch as the time required for clearing vehicular movements from a given intersection, following a "go" period for one highway or the other, is unlikely to require change incidental to changes in the go period themselves, such as may be desirable because of different densities of traffic during'various portions of the day. If, however,

to cause the motor M3 to operate more slowly when longer amber clearing" periods are desired and more rapidly when shorter amber clearing periods are desired.

As hereinbefore indicated, a plurality of traffic signal controllers, such as that indicated in Figs. 1, 2 and 3, may be associated with a single master timer, as, for example, master timer '1 of Fig. 3. Furthermore, it is evident that the operating characteristics of all such local traffic signal controllers thus associated witha given'master timer may be simultaneously revised from such master timer, within certain limits, as to durations of go and stop periods for both the arterial and intersecting highways and for pedestrian periods; however, the durations of the amber lamp clearing periods at the various local controllers are varied by suitable adjustments of the resistance 2B2 thereat to suit the conditions existing at the particular intersections with which they are respectively associated.

In any system comprising a master timer such as the timer T, or one or more local traffic signal U ling mechanism'SC of Fig. 3, the operating characteristics of such local controllers may be further governed from the master timer.

For example, if it is desired to suspend the normal cyclic operation of the local controllers, so that the stop and go signals for the respective highways (as well as the pedestrian periods) will be discontinued, and a flashing amber warn ing signal substituted therefor, as is frequently desired for periods when traflic density is light (say between midnight and dawn)-the switch 242 at the master timer T may be closed, thereby establishing a current path from supply source conductor 250, through conductor 252, winding of relay N, conductor 264 (including switch 242) and conductor 258 (including switch 253) to supply source conductor 256.

The establishment of the current path just described will result in movement of contact H3 into engagement with contacts HI and H2, of contact H5 into engagement with contact H4, and contact H1 away from contact H6.

Such separation of contact H! from contact H6 causes interruption of the energizing current path hereinbefore described for solenoid E; as a result of which, rock shaft I16 will be rotated by spring I70 so as to lift projections of cam followers 80 associated with, and to thereby support, contact fingers 20I, 202', 203, 204', 205, 206, 201, 208', 209, 209", 2I0', 2H, 2H", 2i2, 2I3' and 2M away from the contact strips 16, I6 and 16 with which they might otherwise cooperate; thus suspending "responsiveness of all of said contact fingers to the rotation of their respectively associated cams, and preventing establishment, through any of said contact fingers, of current paths for the lighting of the signal lamps at intersection S; also preventing closure of the lock-up path for relay P, and preventing closure of the energizing path for solenoid J, all of which paths have been hereinbefore more fully described.

The movement of contact H5 into engagement with contact II 4, incidental to such energization of relay N, establishes (independently of the operation of timer mechanism CD) a current path for continuously driving motor M3 from supply source conductor 300, through conductor 304, switch 306, motor M3, resistance 282, conductors 280 and 284, contacts H4 and H5, and conductor 322 to supply source conductor 302.

Engagement of contacts II I and H2 by contact H3, incidental to energization of relay N, establishes current paths for the intermittent lighting of amber lamps A, A, A, A for the arterial and intersecting highways at S, subject to control by contact fingers 2H and/or 2I8' (as determined by positioning of switch 294) through current paths from supply source conductor 302, through contact strip 16, conductor 288, contact strip 16, conductor 286, contact strip 16", through contact finger 2I'I' upon each engagement thereof with said contact strip, if switch 294 is closed, otherwise, through contact finger 2I8', during each closure thereof, thence through conductor 290, to contact H3, from which parallel paths proceed, one through contact HI, conductors 338 and 334 to one of the terminals of each of the amber lamps A, A for the arterial highway, and the other of which paths extends through contact H2 and conductor 344 to one terminal of each of the amber lamps A, A for the intersecting highway; the remaining terminals of said lamps A, A, A, A being connected to supply source conductor 300.

From the foregoing, it will be apparent that, so long as the setting is in accordance with the description just given, if the switch 294 stands open, all of the amber lamps A, A, A, A of the signals at the intersection S, will fiash each time one of the depressed portions of the cam 2IB is presented to its associated follower 80'. On the other hand, if the switch 294 is closed, such lamps will flash whenever a depressed portion of the cam 2II permits contact finger 2 H to move into connection with contact strip 16".

As shown, cam 2I'I has formed therein twice as many depressed surfaces as cam 2 I8, and the setting is such that every other one of the depressed surfaces of cam 2H permits movement of contact finger 2I'I to closed circuit position at a time when some one of the depressed surfaces of cam 2I8 permits contact finger 2I8 to move into closed circuit position. Hence, during operation under conditions now under consideration, if switch 294 is closed, the flashes of the amber lam s at intersection S will be twice as frequent as w en such switch standsopen.

If it is desired to completely suspend response of the local traffic signal controller or controllers associated with a master timer, such as timer T, the switch 253 thereat should be opened, thus interrupting the previously established current paths therethrough which have been hereinbefore more fully described, with resultant denergization of relay N or solenoid E (whichever one had been energized up to that time) so that the rock shaft I76 would thereafter be so positioned as to prevent closure of current paths for lighting any of the signal lamps at intersection S, resultant from positionings of the cams carried by the shaft I04, or resultant from closed circuit positioning of contact finger 2II or 2I8', and, resultant cutting off of the current supply for the motor or motors M2 of the timer mechanism CD of the associated local traffic signal controller or controllers, will cause such motors to come to rest. Referring now to Fig. 3, it will be apparent that if the motor M2 is brought to rest at a time when the shaft H9 is so positioned that the pin I53 is not engaging the arm I55, and the pins I5I' and I52 are not engaging the dog I54, the current supply for motor M3 will thereafter be cutoff upon the next occasion when contact finger 225 is moved away from contact strip 16" by any one of the raised portions of cam 225; unless, upon such occasion, the notch of cam 224 is so positioned as to permit contact finger 224' to connect with contact strip 16".

Furthermore, even should shaft H9 stop in a position such that contacts 6'! are then closed by pin I53 or contact arm I5! is being held in engagement with contact 65 or 66 by the pin I5I' or I52, as the case might be, such fact will not cause rotation of shafts I02 and I04, beyond what would have occurred in the absence of such a contact closure, more than to the extent of the angular distance between raised portions of cam 225.

From the foregoing it will be seen that, opening of switch 253 will result in bringing motors M2 and M3 to rest and in extinguishment of all of the signal lamps at S.

Thereafter, closure of switch 253 will cause restoration of all activities which were interrupted by the opening of this switch, so that such activities will proceed as hereinbefore more fully described.

In situations were a go signal should be given to an arterial highway at all times except following the approach of traffic on an intersecting highway, signal circuit controlling mechanism corresponding to the contacts 236 of master timer T may be arranged for actuation on approach of traffic on the intersecting highway in any wellknown manner, whereupon operation of the remainder of the system'will proceed as hereinbe fore more fully described.

If, on the other hand, equipment is desired for but a single intersection, the master timer mechanism T of Fig. 3 may be omitted; conductors 260 and 268 being, in that event, interconnected at any convenient point; and the local traffic controller timer mechanism CD will thereupon run continuously and suitably control the signal circuit controlling mechanism SC.

With such an arrangement, it is obvious that the adjustments hereinbefore described through utilization of resistance 238 would no longer be effective; however, adjustment of a resistance corresponding to resistance 240 of Fig. 3, would result in shortening or lengthening the operating cycle of shaft H9, and changes in the relative ,III

durations of the respective periods could then be effected by adjustment of the arms II, I52 and Where a plurality of local traffic controllers are associated with a master timer for the purpose of providing for so-called progressive or "rippie" traffic movement,such, for example, as

, indicated by Figs. 9 and 12,--insofar as the needed differences in the settings of various local controllers was found to be represented by other than the time required for a complete cycle of the master timer, such diverse adjustments can be obtained by making the needful settings of the arms I55, I52 and I53 in the various local controllers.

In this connection, it will be noted in a system having local controllers whose arms I5I, I52 and I53 are diversely set, it may be rendered impracticable to orrespondingly revise the relative durations oi the cycle components of all such local contr by merely altering the adjustments of real. ances 238 and 240 at'the master controller in the manner hereinbefore referred to.

Should it be desired to manually direct traffic at an intersection having signals normally ,responsive to a local controller such as that of Fig. 3. such result can be accomplished by manually rotating the cam assembly on shaft I04 in the usual direction, in anydesired manner. Rotation of said assembly in advance of the driving of the motor being permitted by the ratchet wheel 40 and dog 42 shown in Fig. 2. 1

In order that the motor shall not act through such ratchet mechanism to cause movement of the cams in advance of the desire of the operator, the switch 306 of Fig. 3 may be opened for the purpose of suspendingthe operation of motor M3.

After'any such manual aotuationof the cam assembly of shaft I04, the signals thereby controlled may be again brought in step with the master timer T by closing the switch 306, whereupon, operation of motor M3 will proceed until i erate in the intended relationship to the cycle established by the master timer T.

It will be noted that pursuant to the description thus far given, the starting impulses formulated by the timer mechanism CD occur but three times in each cycle. If, however, because of the traffic situation to be served at any intersection, it becomes desirable to provide four starting points in each cycle, this can be accomplished through the utilization of arm I49, and the provision of a pin therein similar to either the pin I5I', I52 or I53, and a revision of the connection to contact finger 224', consisting of withdrawal of said connection from conductor 280 and its application to the conductor associated with such contact as should have a current path closed thereby responsive to such pin as might be so provided in arm I49. Thus, for example, if the pin carried by arm I49 corresponds with pin I52 carried by the arm I52, contact finger 224' should be connected to conductor 214 instead of conductor 280.

The construction and manner of securing the tion of any signal aspect or component thereof, or otherwise.

Fig. 5 indicates the manner in which cams 20I, 202 and 2 I4 are mounted in their assembly group, as being representative of the construction and manner of assembly and mounting of all of the cams comprised by the assemblies associated with the shafts I02 and I04.

These cams are assembled on the sleeve 364, between the spacer rings 362, and each of said cams consists of two relatively movable discs or sections so as to be capable of presenting a greater or less angular raised portion 'depending upon whether the raised portions thereof are in sideby-side or overlapping relationship.

A flanged bushing 366 is secured in one end of the sleeve 364 by means of the pin 368, and another bushing 310 is secured to the other end of the sleeve 364 by means of the pin 312. Said pins 368 and 312 being situated in alignment and extending into the opening through said sleeve so as to engage the slot 314 provided in shaft I04, and thereby enable said shaft to drive said sleeve and the cam assembly secured thereto.

The end of the sleeve 364 which is associated with the bushing 310 has an external thread 316 formed thereon, same being engaged by the nut 318 which clamps the various cams and spacer rings against the flange of bushing 366 in desired positions upon said sleeve.

Each of the spacer rings 362 carries an inwardly projecting pin 380 (see Fig. 6) for engaging an axial slot 382 formed in the sleeve 364.

ranged on each spacer in four groups, with an extra large space between the last line of one group and the first line of the next group. The

positionings of these lines materially facilitate attainment ofdesired settings of. cam configurations, as *w-illbe well understood by those skilled in thisart. 4

As an example of the facility with which the system and equipment hereinbefore described may be adapted for utilization in connection with trafiic signals at intersections having widely diverse characteristics, reference is made to Fig. 10, which" indicates an intersection comprising a main or arterial highway 450, a principal intersecting highway 452, 452 and a minor intersecting highway 454. It is assumed that the traffic conditions are such as render it desirable that, in the absence of trafiic approaching along the minor intersecting highway 454', each cycle of the traffic signal controlling mechanism should alternately provide go and stop signals for the main highway 450 and the principal intersecting highway 452, 452; but that, when trafiic has approached the intersection along the minor intersecting highway 454, it is desired that stop signals shall be given for highways 450 and 452 and that a go signal shall be given for highway 454, the duration of the go signals for highways 450 and 452 being shortened for the then current cycle to an extent sufiicient to provide needed time for movement of traffic from highway 454 into or across the intersection. 

